Magnetron and connection system for magnetron

ABSTRACT

AN ELECTRON DISCHARGE TUBE WITH A COAXIAL PAIR OF CATHODE CONNECTIONS. THE CATHODE VOLTAGE IS SUPPLIED BY MEANS OF A CONNECTION ARRANGEMENT COMPRISING A CLAMPING PIPE AND A PLUG THAT IS SO CONSTRUCTED AS TO MINIMIZE LEAKAGE OF MICROWAVE RADIATION.

atent Inventor Appl. No.

Filed Patented Assignee Priority Marinas Arnoldus Vonk Emmasingel, Eindhoven, Netherlands 848,506

Aug. 8, 1969 June 28, 1971 U. S. Philips Corporation New York, NY.

Aug. 17. 1968 Netherlands MAGNETRON AND CONNECTION SYSTEM FOR MAGNETRON 3 Claims, 4 Drawing Figs.

Int. Cl H01j 25/50 [50] Field of Search .4 315/3951, 39.53, 39.73

[56] References Cited UNlTED STATES PATENTS RE23,517 7/1952 Litton 315/39.53X

2,128,233 8/1938 Dallenback 315/39.53X

2,607,898 8/1952 Nelson 315/39.53X

2,747,137 5/1956 T0nks.. 315/3953X 3,443,150 5/1969 Staats 3l5/39.53X

Primary Examiner Herman Karl Saalbach Assistant ExaminerSaxfield Chatmon, .lr. Attorney-Frank R. Trifari ABSTRACT: An electron discharge tube with a coaxial pair of cathode connections The cathode voltage is supplied by means of a connection arrangement comprising a clamping pipe and a plug that is so constructed as to minimize leakage of microwave radiation.

PATENTEUJUN28I9YI 3,588,5 9

SHEET 1 OF 2 INVENTOR.

MARINUS A. VONK ACE/V7 PATENTEDJUN28I97I sum 2 or 2 INVENTOR,

MARINUs A. VONK MAGNETRON AND CONNECTION SYSTEM FOR MAGNETRON The invention relates to a magnetron in which a cathode is supported by a coaxial cathode connection which is passed to the outside through one ofthe pole shoes and which comprises within a conductive tube a conductive rod which is separated from the tube by an insulator. The invention furthermore relates to a connection system for such a magnetron.

Such a magnetron having a helical cathode is known from US. patent specification 3,289,023. The rod is secured to the tube by means of an annular insulator, while the tube is connected to the housing of the magnetron by means of a conical insulator. In this case the drawback presents itselfthat a larger microwave radiation than is desirable can occur from the annular insulator which separates the conductors from the cathode connection, which radiation is not suppressed by a conventional filter for TV and radio radiation.

It is the object of the invention to provide a device with which too large a microwave radiation can be checked.

According to the invention, in a magnetron of the type mentioned in the preamble, a connection system is clamped to the cathode connection which connection system comprises a plug which comprises two coaxial rings connected at one end by a disc-shaped part, ofwhich rings the innennost clamps the said rod, and which connection system comprises a clamping pipe which clamps the said tube, said clamping pipe extending in the space between the said rings in such manner that it constitutes a choke.

It has been found that the undesirable microwave radiation from the cathode connection can be suppressed for the greater part by means of the simple connection system described which can be provided a simple manner on the outside ofthe magnetron.

The invention also concerns the connection system as described which can be connected to existing magnetrons.

It is noted that a magnetron provided with a choke for the cathode connection is already described in Proceedings of the l. E. E. (voLIII, No. 1, Jan. l964, p. 52). However, in this case the choke is arranged on the inside which often meets with practical difficulties.

In order that the invention may be readily carried into effect, it will now be described in greater detail, by way ofexample, with reference to the accompanying drawings, in which:

FIG, I is a cross-sectional view parallel to the axis of the magnetron according to the invention,

FIG. 2 is a cross-sectional view at right angles to the axis,

FIG. 3 shows the connection system for the magnetron mainly in a cross-seetional view,

FIG. 4 is an elevation in the direction of the axis of the connection system.

Referring now to FIG. 1 reference numeral 1 denotes the anode construction, The cathode connection is formed by the rod 6 and the tube 2 which is coaxial with said rod. The actual cathode is the helical wire 3 which at one end is secured to the end flange 4 of the tube 2 and at its other end is connected to the plate which is supported by the rod 6. The flange 4 and the plate 5 also serve as end rings to focus the electrons on the inwardly directed ends of the anode segments. The cathode connection is supported by the conical insulator 7 secured to the anode cover. Inside the anode cover the poleshoes 10 are situated. The actual anode 8 which is situated within the annular anode housing 12 comprises the interaction space 9 which is bounded by the ends of the anode segments 13.

The anode segments 13 constitute the resonant cavities 14 as shown in FIG. 2. The anode segments are alternately connected to the conductive rings 16 and 17 which extend in the profiled grooves 18 of the anode segments on the side of anode segments remote from the cathode support 2. A transverse connection 15 which ends in the anode segments which bound two successive resonant cavities, is connected to the inner conductor 23 of the coaxial line of the output coupling system. The outer conductor of the coaxial line is denoted by 19.

In FIG. I, the output coupling system as a whole is denoted by 11. The outer conductor 19 terminates in the flange 22, to which the flange 21 ofa connection ring 20 of the conical insulator 25 is secured. Within the conical insulator the inner conductor 23 terminates in a hollow pin 24 which can be coupled further to a coaxial line or can be inserted in a resonant cavity ofa waveguide.

The connection system for the cathode connection in FIG. 1 is denoted by 100. FIG. 1 shows the plug assembly comprising an inner hollow cylinder 102, an outer hollow cylinder 10], and a disc H2. The inner hollow cylinder 102 within which the clamping sleeve I03 clamps the rod 6 provides an electrical connection through the screw 104, The clamping of the clamping sleeve is obtained as a result of the conical shape ofthc ends of the inner ring 102 and the clamping sleeve 103. The clamping pipe 105 is clamped around the tube 2 by means of the brace 106 comprising a clamping pipe assembly.

FIG. 3 shows the connection of the supply lines and 111. This FIG. furthermore shows one of the three gaps 107 which divide the clamping sleeve in the resilient lugs. The clamping pipe comprises four gaps 108, which divide the clamping pipe in resilient lugs.

The plug 101 is preferably provided with cooling fins 109 as shown in FIG. 4, so that the temperature of the metal insulator connections can be kept below a desirable value by means of a current of air which is also used to cool the anode system.

lclaim:

I. An electron discharge tube comprising a hermetically sealed envelope, a cathode within said envelope, a pair of coaxial conductors for supporting and providing connections for said cathode, said coaxial conductors comprising an inner and outer conductor passing through said envelope and insulating means for vacuum support of said conductors, and a connection arrangement positioned at the external ends of said inner and outer conductors to supply a voltage to said cathode through said coaxial conductors without leakage of microwave radiation, said arrangement comprising a clamping pipe assembly and a plug assembly, said clamping pipe assembly being clamped on said outer conductor and forming an extension for said outer conductor, said plug assembly comprising two coaxial cylinders connected by a disc, said two coaxial cylinders comprising an inner hollow cylinder and an outer cylinder, said inner cylinder being clamped on said inner conductor, and said clamping pipe assembly extending into space between said inner cylinder and said outer cylinder to form a microwave choke.

2. A connection arrangement for supplying voltage to a cathode supported by coaxial conductors extending through a hermetically sealed envelope of an electron discharge tube comprising a clamping pipe assembly externally clamped on an outer conductor of said coaxial conductors and forming an extension for said outer conductor, and a plug assembly comprising an inner hollow cylinder, an outer cylinder coaxial with said inner cylinder and a disc connecting said inner and outer cylinders, said inner cylinder being clamped on said inner cylinder being clamped on said inner conductor, and said clamping pipe assembly extending into space between said inner cylinder and said outer cylinder to form a microwave choke.

3. A connection arrangement as claimed in claim 2 wherein said plug assembly comprises external cooling fins.

mg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent 358L589 Dated June za mn lnventorQs) MARINUS ARNOLDUS VONK It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 14, change "105 to -l00- line 62, delete "cylinder being clamped on said inner" Signed and sealed this 2nd day of November 1971.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Acting Commissioner of Patents 

